1. Field of the Invention
The present invention relates to an image data processing method for printing digital facial images of improved quality, and more particularly to a facial region detection device and a correction method for photoprinting, which is a type of image processing technology for detecting and separating a facial region from inputted image data and conducting various kinds of distortion and color correction.
2. Description of the Prior Art
As generally known in the art, digital imaging systems have been widely used recently, and they can not only conduct compression and storage, but also improve and modify image quality through image processing.
When digital images are to be printed by a photoprinter based on the processing by a digital imaging system, color distortion or any other undesirable factors existing in facial images are preferably removed so that the printed facial images have better quality than what is supported by the performance of the photoprinter itself.
Such image processing systems for photoprinters have been extensively studied by various corporations manufacturing printers and cameras. Conventional technologies in this regard are commonly characterized in that a facial region is separated based on the skin color distribution and typical facial patterns, and the separation process is followed by color correction, which primarily aims at correcting the red-eye effect, lips, skin color, hair color, etc.
However, the prior art has a problem in that, when the face has been rotated in the image data, the face is not correctly detected. In addition, although the red-eye effect and the darkening of skin color by backlight are corrected, no correction is conducted with regard to the reflection caused by flashing or lighting. When images are stored at a high compression ratio with low image quality, the block boundaries are created.